I'm trying to find out what the codes mean on the Holley carb so I can find out what part number I need for the rebuild or trick kit for my carb. The numbers on the choke air horn are listed as followed:

3878261-EH
LIST-3310
124

What is the first row of numbers?

I'm assuming this is the first generation 3310 because it doesn't have -1,-2,-3,-4, etc..

Is the last code the date code? When was it made?

I think it's a 780cfm 4150 model. Am I right?

What kit do I need?

I once heard from an ex Holley employee that the 3310 is and always has been a 780 cfm vac sec carb. The 3310 that is now called a 750 is done so because the flow bench was tweeked to make the carb flow the smaller numbers to help sell the larger carbs.

Take a look at http://www.holley.com I would think you can match your numbers there and find the right kit...

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...Dennis
The Cars:
'69 RS Convertible w/SS trim (http://www.camaroslimited.com/memberscars/den.htm)
'96 Z28SS #1679 of 2410 (http://www.camaroslimited.com/graphics/memcars/96ss.jpg)
The Club:
Camaros Limited Nor-Cal (http://camaroslimited.com)

This 780/750cfm 3310 Holley carb stuff has bugged me for years.

I thought I read somewhere that an original 780 3310-1 had "dogleg" boosters in it whereas the 750 carbs have the "straight" kind and that the "dogleg" boosters were worth the extra 30cfm.

Anybody got the staight skinny on this???

I do know I read that Honest Charlie said for the money a 780cfm 3310 was the "runnin'est" carb ever made. pdq67

The carb is for a 65 Chevelle 396 ci, 425 hp. Downleg booster 3310's were 780 cfm, and straightleg booster 3310's were 750 cfm.

The 3310-1 is a 780 with a secondary metering block and changable jets. The 3310-2 and -3 are 750 cfm with a secondary metering plate and no jets.

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'69 RS/SS396 pro street
427/4spd/9"

Even easier... The original 3310-1 was a holley 780 Vaccum Secondary Carb. It was different than other 750 Vac Secondary carbs by the same number because it contains a second metering block in the rear of the carb, when the newer style Vac Secondaries simply act with the small metering block inside the bowl. If the carb has the second metering block, it is a safe bet that your carb is a standard 780, which was original equipment on some old chevelles, camaros, mustangs, torinos, and even a handful of Ford pickups, incase you are looking for replacement parts.

Hope this helps